Mr Overd was convicted of a public order offence in March, following a conversation with a man self-identifying as homosexual, who objected to Mr Overd's preaching.

Passing judgment in March, District Judge Shamim Ahmed Qureshi took the extraordinary step of ruling on which Bible verses it was appropriate for Mr Overd to use in his public explanation of the Bible's teaching on homosexual practice.

'Chilling effect'

Mr Overd welcomed today's decision, but said that the case should never have come to trial in the first place:

"I give thanks to God for today's vindication. I have known God's peace and presence throughout this difficult time.

“Today the Court was faced with the farcical situation of a witness telling the judge that he couldn't even remember what I had said, but simply asserting that it was 'homophobic' – as though the mere assertion that something is 'homophobic' is enough to curtail free speech.

"In this country, we are now in the ludicrous situation where the slightest accusation of a 'phobia', be it 'homophobia' or 'Islamaphobia', is enough to paralyse rational action by the police and authorities. The highly politicised dogma of ‘phobias’ now too often results in trumped up charges and legal action. There is a chilling effect.

"Reasonable, law-abiding people now feel that they can't say certain things and that is dangerous. Totalitarian regimes develop when ordinary people feel that there are certain things that can't be said.

"Rather than prizing freedom of expression and protecting it, the police and the prosecutors risk undermining it, because they've become paranoid about anyone who might possibly feel offended.

"My motivation in all my preaching is to share God's message of love and forgiveness through Jesus Christ. To do that I have to talk about the reality of life, including our sinfulness."

Mr Overd, who regularly preaches on the streets of Taunton, was represented in court by Michael Phillips, an allied solicitor of the Christian Legal Centre.

The judge awarded costs in Mr Overd's favour.

'Canary in the coal mine'

Andrea Williams, chief executive of the Christian Legal Centre, welcomed today's decision and highlighted how Mr Overd's case ought to be a warning to the government over its 'extremism' plans:

"This is the right decision, but it should never have come to this. Mike Overd is motivated by love and simply wants to share the good news of Jesus Christ.

"Public debate is becoming more superficial and fragile. People feel that certain things can't be said. That is dangerous. It prevents us from challenging ideas, beliefs and behaviour that need to be challenged. It may make some people feel more comfortable, but it doesn't make the country safer.

"Mike's case highlights problems that will only get worse if the government ploughs on with its flawed 'Counter-Extremism Strategy'. Islamic terrorism needs to be tackled, but giving the government far-reaching powers to clamp down on all sorts of beliefs that it doesn't like is dangerous.

"The definitions and parameters are so vague that, on a whim, the government could turn on almost any viewpoint that it doesn't like.

"Mike Overd is a canary in the coal mine, warning us of the dangers of the government's current approach to tacking 'extremism'."

'Fraught with risk'

In July, Lord Evans, former head of MI5, warned:

“The forthcoming Counter-Extremism Bill aims to crack down on extremism but definitions will be crucial, and implementation of the new powers will be fraught with risk.

"One can imagine already the powers being used against harmless evangelical street preachers or the like, out of misplaced zeal and a desire to demonstrate that they are not directed against one religion alone."